The present invention is directed to a filling machine for supplying liquid under counterpresure into a container and includes a filling machine vessel, a valve support body for filling a valve and a gas return tube and valves in the support body for controlling preliminary air, return air, and a vacuum as well as a piston-cylinder unit for moving the filling valve.
A known filling unit has a bottom portion carrying the container contact pressure seal of the unit which is vertically supported at the lower end of the filling valve head portion and is movable by a piston cylinder unit located opposite to the filling valve head portion. The cylinder is connected to a stressing or pressurizing gas, so that prior to the commencement of the filling operation during the pressurizing of the seal against the bottle by the stressing gas, a contact force must be provided depending upon the pressure to be sealed off. The effective piston surface is selected whereby the desired contact force or pressing force is established.
In this arrangement there is the disadvantage that the piston-cylinder unit is located at the bottom end of the filling valve head portion in the region around the liquid valve in the head portion. Due to this arrangement, the design possiblities are extensively limited. In this known arrangement, the outflow bushing between the liquid valve and the lower end of the filling member must be comparatively long with the result that it acts counter to optimum liquid guidance and is disadvantageous with respect to the uniformity of the filling height. Moreover, the arrangement of the liquid valve must be adapted to the remaining space whereby problems occur with respect to the filling operation affecting a reduction in and the quality of the filling material and the filling speed.